Mine isn't burned in yet so I don't want to say anything other than it drives HE400 VERY well. Personally, I only really believe in extended burn in when it comes to speakers that actually have a diaphragm, but I burn in everything before talking about it anyway just to be sure and so others don't have to ask me about it. I do have a couple questions for other owners. Do the internals of your Glaciers feel kind of loose inside the case? Mine is a little. Do you ever have to use the reset? I've had to a couple times and am trying to isolate what causes it, ie plugging into wall, plugging power into computer, plugging into DAC, etc. Just curious, although if the reset has to be used regularly I will be annoyed.